Leather skiving machine or splitter



Sept. 26, 1950 R. w. HALL LEATHER SKIVING MACHINE 0R SPLITTER 6 Sheets-Sheet 1 Filed July 19, 1947 INVENTOR. BaZvfi WHa/Z Sept. 26, 1950 R. w. HALL LEATHER SKIVING MACHINE 0R SPLITTER 6 Sheets-Sheet? Filed July 19, 1947 a ww Q INVENTOR. W 522]] P 1950 R. w. HALL 2,524,013

LEATHER SKIVING MACHINE 0R SPLITTER Filed July 19, 1947 6 Sheets-Sheet 5 INVENTOR.

Sept. 26, 1950 R. w. HALL 2,524,013

LEATHER SKIVING MACHINE OR SPLITTER Filed July 19; 1947 6 Sheets-Sheet 4 IN V EN TOR.

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LEATHER SKIVING MACHINE OR SPLITTER Sept 26, 1950 6 Sheets-Sheet '6 Filed July 19, 1947 INVENTOR: fiaip]: W H Z] 2 22 zgzy g .4 7 s.

Patented Sept. 26, 1950 LEATHER SKIVING MACHINE OR SILITTER Ralph W. Hall, Cincinnati, Ohio, assignor to The Randall Company, Cincinnati, Ohio, a corporation of Ohio Application July 19, 1947, Serial No. 762,177

9 Claims. 1

This invention relates to improvements in a leather skiving machine, splitter, or the like.

One object of the invention is the provision of means for gaging or indicating the proper tension of the skiving knife blade or band.

Another object of the invention is the provision of means for indicating the proper tension of skiving knives of varying lengths, said means requiring no adjustments after the completion of the initial assembly.

A further object is the provision of a roller construction whereby roller pressure upon a piece of leather of unequal thickness will be equalized as the skivin operation is performed.

Another object of the invention is the provision of an improved motor suspension whereby the belts of a pair of motor pulleys will automatically equalize their tension in driving a continuous grinding apparatus for the band knife.

Another object is the provision of means, in connection with the grinding wheels, for visually ind cating the width of the ground bevel on the cutting edge of the skiving knife blade or band.

Another object is the provision of means for adjusting the head of the skiving machine in relation to the fixed path of the skiving knife, to

' obtain a square and accurate setting thereof.

Another object of the invention is the provision of means for gaging the maximum width of leather to be fed into the machine for skiving.

A further object is the provision of means for expedit ously adjusting the space between the knife blade and the pressure roller to accommodate a predetermined thickness of leather prior to the skiving operation.

Another object of the invention is the provision of means whereby the head of the machine may be swiveled in relation to the knife blade, making possible the skiving of two or more pieces of leather of different thicknesses at the same time, thus increasing the productivity of the device.

These and other objects and advantages are attained by the means described in the following specifications and illustrated upon the accompanying drawings, in which:

Fig. 1 is a front elevational view of the skiving machine embodying the improvements herein described, parts being broken away for clarity of illustration and description.

Fig. 2 is a side elevation of the skiving machine.

Fig. 3 is an enlarged fragmental perspective view of the swivel head, with parts broken away for clarity.

, Fig. 4 is an enlarged cross sectional view of Q 2 the skiving knife blade tensioning mechanism and knife tension indicator.

Fig. 5 is a cross-sectional view showing in side elevation the grinding wheel motor suspension.

Fig. 6 is a fragmental top view of the skiving machine, ShOWlng the bevel indicator arrangement and the means for adjusting the swivel plate. I

Fig. 7 is an enlarged plan view taken on line l'! of Fig. 5, showing the construction of the swivel plate, and its relation to the swivel block and swivel pin.

Fig. 8 is a longitudinal cross-sectional view of the head control mounting means. I

Fig. 9 is a transverse cross-sectional View of the roller assembly and knife support.

Fig. 10 is an enlarged fragmental view of the pressure roller assembly in elevation, with parts broken away for clarity of illustration.

Fig. 11 is an enlarged perspective view of a step flange collar used in spacing the pressure roller in relation to the skiving knife.

Fig. 12 is a cross-sectional view of the step flange collar taken on the line i2-l2 of Fig. 11.

Fig. 13 is a fragmental view, partly in cross section, showing the application of the step flange collar in relation to the pressure roller setting screw.

Fig. 14 is a cross-sectional view slightly enlarged, taken on line Hl-l 4 of Fig. 4.

Fig. 15 is a vertical cross-sectional view of the pressure roll spring mounting means.

Machines for skiving leather and kindred materials are in general usage for producing thin sheets employed in the manufacture of bill folds, bags and cases of various types, shoe parts, and many other articles of commerce incorporating thin flexible sheet leather and similar materials. Such machines heretofore have given notoriously poor service in the performance of their intended functions, due to their relative inflexibility of operation, their inability to process with equal effectiveness all grades or weights of raw material, and various other limitations most of which result from the varied nature of the materials to be processed. The limitations which impair the usefulness and efficiency of such machines are well known in the trade, and manyefforts have been advanced in the past with the purpose of overcoming some of the difficulties, but the market still has been seeking a satisfactorily operative and serviceable machine which is capable of advanced universal usage and productiveness. The machine of the present invention has proven itself greatly superior to others heretoshownin Figs. 3 and 5.

fore offered to industry, in its ability to process raw materials varying considerably as to weight, size, hardness, and uniformity of thickness, and in addition, provision has been made for maximum continuity of operation by reason of mechanical improvements, and the incorporation of means permitting a plurality of different skiving operations simultaneously. Various other advantages of merit in the improved machine will become manifest to those skilled in the art, as the description proceeds.

As exemplified in Fig. l, the head, generally indicated by the character I5, is mounted on the bed l6, which in turn is supported by the legs l1 and I8. The head l5 rests directly upon the upper flat surface is of the forwardly extending central portion I4 of bed It, being universally slidable .thereon within defined limits. Clamprails 28-29 are suitably secured to the upper fiat bed surface it, transversely thereon, one on each side of the head base plate 2|. Each of the clamp rails 29 is provided with a rabbet, as shown, to slidably engage the tongues 22 of correspondingrabbets provided on the outer ends of the head base plate 2|. The clamp rails serve to prevent vertical displacement of the head Hi from the bed It and to limit the swiveling movement of the head. The clamp rails 20 are set a suficient distance from the head base plate 21 to provide spaces 23 therebetween, in 2:

on the median line of the base plate, into which :2

is slidably disposed the swivel plate 26. This swivel plate, like the head base plate 2|, also takes its bearing on the upper flat surface I9 of the bed IS, the swivel plate ends 21 and 28 extending substantially beyond the front and .1

rear respectively, of the head base plate 2|, as The swivel plate 26 is also slidable upon the upper flat surface IQ of the bed, means being provided for sliding the swivel plate independently of the head l5, as requirements demand in the operation and adjustment of the machine. The manner of swivel- .ing the head and moving the head forwardly and rearwardly upon the bed will be hereinafter fully disclosed.

An endless band knife 29 (Fig. 1) tracks upon a pair of horizontally aligned coplanar rotating .drums 3B and 3|, mounted at opposite ends of the bed I6. The knife, on its upper run, passes through openings 32 (Fig. 3) provided in the head uprights 34 substantially centrally thereof, then passes under the forwardly extending central portion 4 of the bed |6 on its lower run. The

knife 29 performs a splitting or skiving action on leather or other material as said material is shaft housings 4| and 42 respectively, said shaft housings being swivel mounted upon the bed l6 adjacent the outer ends thereof. The pulley belt 31 and pulleys 38 and 39 may be protected by ,means of the belt guard 44.

Means may be provided for adjusting the knife blade 29 to track true upon the drums and against the drum flanges 43. Adjusting means in the exemplified form comprises a pair of blocks (Fig. 6) secured at opposite sides of each drum shaft housing and near the outer end thereof. The blocks 45 are provided with tapped holes for the reception of set screws 46. Loosening either screw and tightening the other will swivel the housing about its pivot, the adjustment being completed when the knife tracks true upon the drum and against the flange 43. While Fig. 6 shows only the adjusting means for drum shaft housing 4|, it is to be understood that similar adjusting means is provided for drum shaft housing 42 at the opposite end of the bed H5. The knife blade 29 always travels in a fixed path upon the drums 30 and 3| and through the head I5, regardless of the angularly swiveled position of the head [5 or the forward or rearward position of said head upon the bearing surface l9.

In performing the skiving or splitting operation upon leather or other material, the knife blade 29 must be set at the proper tension. It is also necessary, in order to prolong the life of the blade, to release the working tension of the knife when the machine is not in use, as overnight, for instance. It was formerly a matter of guess work to obtain the proper working tension at the beginning of each days work, an operation which required an undue amount of time on the part of an inexperienced or unskilled operator. With the knife tension indicator about to be described, it' is a simple matter for any operator, however inexperienced, to obtain the proper working tension of the knife blade 29, thus obviating the objections encountered in former skiving machines.

While the drum shaft housing 4| is fixed against further movement after the drum adjustment has been made as described in a preceding paragraph, the opposite drum shaft housing 42 is mounted for shifting movement upon the bed I 6 for tensioning the knife blade 29. The base plate 48 of the drum shaft housing 42 (Fig. 2) is provided with a rabbet on the front and rear edges thereof, the tongues 49 of the rabbeted edges being slidably engaged by correspondingly rabbeted guide rails 5!! and 54, longitudinally bolted or otherwise fixed to the bed l6, as shown. Mechanism for tensioning and untensioning the knife blade 29 and for indicating the proper Working tension, shown clearly in Fig. 4, is actuated by rotating the hand wheel 5|, the shaft of which extends through the side wall 52 of the bed l6.

Clearance is provided in th upper surface 53 (Fig. l) of the bed l6 for the free reciprocal movement of the bored sleeve support 55, suitably attached to the drum shaft housing base 48, as by means of the bolts 55, said clearance being indicated at 5? in Fig. 1. The drum shaft housing 42, drum shaft 48, drum 3|, and knife blade 29' are indicated by broken lines in Fig. 4. The sleeve support member 55 is rigidly secured to the inner telescoping sleeve 58 which takes a sliding fit on the large diameter 59 of the tension shaft 60. The sleeve support 55 abuts a shoulder 6| on the sleeve 58 and is confined thereon by means of a nut 62 screwed on the threaded end 63 of the sleeve. A look washer 65 may be interposed between the end 65 of the sleeve support 55 and the nut 62. The outer telescoping sleeve 51 takes a sliding fit on the inner sleeve 58 and is supported at its outer end by the sleeve bearing 68 fixed to the under side of th bed I6 as by means of bolts 69. The bearing 68, bored to receive the outer sleeve 6? in a sliding fit, is in axial alignment with the sleeve support 55, said alignment being substantially parallel to the travel of the band knife 29.

At the free end it of the sleeve 61 is disposed a nut "H, fixed thereto against rotation, as by means of screws, welds, or the like. The nut H receives the threaded end 12 of the tension shaft 60. This shaft is confined against longitudinal movement by means of a flange 13 provided near the outer end of the shaft and held against the outer face of the bed wall 52 by the shaft bearing 15 which is recessed to receive the flange it. To receive the thrust of the shaft 50, a bored plate or washer 15 may be interposed between the outer face of the end wall 52 and the inner face of the shaft bearing 75, these two members being secured to the end wall 52 by means of screws ll. Keyed or otherwise fixed to the outer end 18 of the tension shaft 65 is the hand wheel 5i, which may be secured against displacement by the nut 19. A clearance hole in the end wail 52, through which the tension shaft extends, is indicated at 8E3.

A tension indicator tube carrier 82 (Fig. 4) provided with a large split bore 83 (Fig. 14) is clamped to the inner telescoping sleeve 58. The clamp portion 85 of the tube carrier abuts the inner face 8? of the sleeve support 55. Clamping is obtained by tightening the screw 88 inserted through the a-pertured cars 89 of the tube carrier 82, the split being indicated at 90 in Fig. 14. The tube carrier arm ill which extends laterally from the clamping portion 85 of the tube carrier '82 is provided at its outer end with a smaller bore 85, substantially parallel to the split bore 83, into which is inserted the tension indicator tube 92. This indicator tube extends through the clearance hole 53 in the end wall 52, and through the tube support 95, in which it takes a sliding fit, said tube support being secured to the end wall 52 by suitable means, such as screws or the like. The tube support 95, and the bore 85 in the indicator tube carrie 82, are, of course, in axial alignment. The indicator tube 92 is secured to the tube carrier 232 by means of the set screw 96, so that movement of the tube carrier 82 imparts the same movement to th indicator tube 92.

A tension indicator rod carrier 91, similar in construction to the tension indicator tube carrier 82, is clamped to the outer telescoping sleev 61, substantially midway of the ends thereof, clamping being obtained by tightening the screw 93. The tension indicating rod 99, substantially longer than th tension indicating tube 92, takes a sliding fit through said tube. The end MD of the indicating tube 98 is inserted through the bore Iii! of the tension indicator rod carrier 5?,

and is secured therein by means of the set screw I02, so that movement of the indicator rod carrier 91 imparts the sam movement to the indicator rod 99, which, as shown in Fig. 4, telescopes into the indicator tube 92. Between the tension indicator tube carrier 82 and the end 403 of the outer telescoping sleeve 5?, and encircling the innor telescoping sleeve 53, is the compression spring Washers W5 may be provided, against which the ends of the spring abut.

Thus it will be seen that as a clockwise rotation of the hand wheel BB is initiated, through 'the threaded engagement of the tension shaft 60 with the nut ii, the first action is the movement of the outer telescoping sleeve 57 to the right, as viewed in Fig. l, against the force of the spring I05. As the outer sleeve 61 is thus drawn to the right, telescoping on the inner sleeve 58, the clamped-on tension indicator rod carrier 91 also moves in the same direction, taking with it the tension indicator rod 99 which telescopes into the tension indicator tube 92. Continued clockwise rotation of the hand wheel 5! increases the compression of spring "35 against the tension indicator tube carrier 82 fixed to the inner telescoping sleeve 58, and in fixed relation to the drum shaft housing 42, moving the last named sleeve also to the right on the tension shaft 60. Since the drum shaft housing 42 is fixed to the inner telescoping sleeve 58 by means of the shaft housing base t8, and the sleeve support 55, movement of the inner telescoping sleeve 58 to the right takes with it the drum 3!, upon which is tracked the band knife 29. As the compression on the spring I05 increases, the tension indicator tube carrier 82 moves the tension indicator tube 92 to the right through the tube support 95. While the tension indicator tube 92 is moving to the right, the tension indicator rod 99 is also moving in the same direction through said tube, but at a faster rate of travel. When the proper adjustment for the working tension for the band knife 29 has been established, the outer faces I58 and H39, respectively, of the tension indicator rod and tube will be in flush relation, as indicated at ill! in Fig. 4.

In setting up the knife tensioning mechanism, the set screws as and l 82 on the tension indicator tube carrier 82 and the tension indicator rod carrier 91, respectively, are left unscrewed. The hand wheel 5i is then turned until the proper working tension is obtained on the band knife 29. When this has been definitely determined, the indicator tube 92 is positioned to protrude slightly outside the tube support 55 on the wall 52 of the bed l6, as indicated in Fig. 4. The tension indicator rod 89 is then positioned so that the end face H38 thereof is flush with the end face 39 of the tension indicator tube 92. The set screws 55 and H32 are then firmly tightened.

Thereafter, when the tension on the band knife is released, which should be done at the end of each day or whenever the machine is not in use, in order to prolong the life of the knife, the tension indicator tube 92 will recede into the tube support 95, and the tension indicator rod 99 will recede into the tube. It is then a simple matter to re-tension the knife 29 by turning the hand wheel clockwise until the end faces of the indicator rod and tube are flush, as at Nil. If the rod protrudes beyond the tube, the tension on the knife is too great. In that case, the hand wheel is turned counter-clockwise to bring the rod end face flush with the tube end face. Thus it will be seen that even the most unskilled operator will be able to obtain quickly the correct workingtension of the band knife by means of the tension indicator described above, without the use of guess work or an undue loss of time.

Since band knives vary slightly in length, and these knives must be replaced on the machine from time to time, as they become Worn, it is essential that the tension indicator be equally effective on such knives of varying lengths. The design of the present invention positively assures this accurate gaging of the knife tension regardless of length variation which normal trade tolerances allow. The double action of the sleeve 6! compressed against the spring Hi5 and the said spring compressed against the drum shaft housing 42, with the associated indicator rod and tube,

7 as built into the present invention, never fails to give a correct reading of th band knife tension, regardless of normal variations in the lengths of such band knives.

As a protective measure, guards may be provided for the drums, such as indicated at I I and I f2 (Fig. 1). These drum guards, arcuate in form, are detachably supported by means of clamp screws I I3 pivoted on the drum guard brackets I I and I I6, suitably mounted behind each drum. Drum guard support I I5 may be mounted directly upon the drum shaft housing 4i However, in order to provide clearance for any slight movement of the drum shaft housing 42 necessary for tensioning and untensioning the band knife 29, the lower part of the drum guard support H5 may be bifurcate, as indicated in Fig. l, the legs of the bit rcation spanning the said shaft housing and mounted upon the rabbete'd guide rail 54, (Fig. 2).

The machine is provided with two sets of knife guides, one directly behind the feed rolls, as shown at Iii in Fig. 9, and the other at the grinding station, as indicated at I I8' in Fig. l. The knife guides If? (Fig. 9) are mounted upon the knife guide supports HS, which in turn are supported between the head uprights 34 (Fig. 3) and held against displacement by means of the screws I Ilia. In order to preclude displacement and distortion of the knife when leather or the like is being fed to the said knife, a backing blade I is provided, which is supported by the plate EZI mounted upon an adjustable back bar I22, shown in Figs. 2, 3, and 6. The back bar is mounted on back bar supports I23 by means of adjusting screws I25. The knife guides H8 are mounted in suitable brackets depending from the bed IE5 (Fig. 1).

Oil-moistened pads bear upon the upper run of the knife at each side of the head I5, as at 526 (Fig. 1) while the lower run of the knife passes through oil soaked pads I21, depending from the bed I5 and disposed on each side of the grinding station, the purpose of these pads being to remove dust particles and other extraneous matter which might interfere with efficient operation of the machine. The oil pads I25 are mounted on the drum guards by means of pivoted links (24.

A pair of vertically aligned parallel feed rolls I28 and 525 are horizontally mounted in the head I5 (Fig. 9) and rotated in opposite directions toward the beveled forward edge 30 of the knife 29, said rolls being driven by means of the motor ISI (Fig. 6) and gear box I32 through the sprockets I33 and the right and left hand spiral gears 435 and E35 (Fig. l) keyed to the rolls I28 and I29, respectively. A sprocket guard is indicated at 53?.

l he upper feed roll I25 is called the gauge roll because it controlsthe thickness of the split of leather. This roll, which may be solid, is journaled in bearings I 3hr (Fig. 3) mounted in the vertically adjustable gauge roll carriage E33 mounted upon the head, the up and down movement of which is controlled by the hand wheel I39 centrally disposed upon the sprocket housing i4!) atop the head I5. Within the housing is a chain and sprocket mechanism for rotating in unison the screws hi3 which elevate and lower the gauge roll carriage I38. Adjusting means for aligning the gauge roll in parallelism with the band knife 29 are indicated as adjusting collars I42 threaded upon the screws G53 and locked by the lock nuts I4I when the proper adjustment has been made by rotating the collars within the smoothly-bored brackets W5 fixed to the carriage.

The gauge roll carriage I38 is also provided with pressure pin limit gauges (Fig. 9), one at each end of said carriage, An extension or boss I41, which may be integral with carriage I38, is bored and counterbored to receive the vertical pressure pin I48 having an enlarged flange por tion I49 against which the coil spring I50 abuts, as shown in Fig. 9. The pressure pin I48 is also provided with an upper shank I5! encircled by the compression spring I 50. The spring is confined against displacement by the cover plate I52, held in place by means of screws, suchas I53. Means for setting the pressure pin to limit the downward movement of the gauge roll carriage I38 may be provided, such as the set screw I55, in threaded engagement with a tapped hole in the cover plate I52. The spring I59 constantly urges the lower face I54 of the pressure pin into contact with the feeding table 33. By means of the set screw I55, the end of which abuts the upper face of the pin shank portion I5I, the pressure pin I48 may be set to the point where the minimum working space between the gauge roll I28 and the cutting edge of the knife 2-9 is obtained. Thus, on rotating the hand wheel I39 atop the head I5, maximum downward movement of the carriage and gauge roll is reached when the pressure pin I48 strikes the set screw I55, eliminating the danger of the gauge roll I28 coming into contact with the rotating band knife 29.

The shaft of the hand wheel I39 is provided with a calibrated dial I56 (Fig. 3) mounted upon a sleeve I51 rotatable on said shaft. A pointer or mark I58, on top of the sprocket housing I4U- adjacent the calibrated dial, is used in setting the gauge roll I28 for different thicknesses of leather splits. The sleeve I51 may be provided with a lock screw I59 for locking the calibrated dial to the hand wheel shaft when said dial reads zero in relation to the pointer or mark I58. When the gauge roll I28 is set at zero, as explained above, the pressure pins I48 will be in contact with the upper surface of the feeding table 33, and a thin split of leather will result. If a heavier split of leather is desired, the hand wheel I38 is rotated to elevate the gauge roll I28 the desired distance from the blade 29, the calibrations on the dial I determining the desired thickness of the split. When the gauge roll is so elevated, the springs i513 will urge the pressure pin I48 into contact with the feeding table 33.

In addition to limiting the downward movement of the carriage I38 with its associated gauge roll I28, the pressure pins I48 serve to act as limit means for determining the maximum width of leather sheet which may be fed into the machine, said pins being spaced in correspondency with the maximum working length of the feed rolls I28 and I29.

. In order to prevent upward distortion or bowing of the gauge roll as leather is fed to the knife, an elongated reinforcing means or bar may be provided, such as shown at I59 in Fig. 9. A screw I51 serves to adjust the reinforcing member I60. With the gauge roll 28 thus reinforced against upward distortion or bowing, a uniform thickness of the leather split is assured as leather is fed to the knife 29.

The lower feed roll M29 is called the pressure roll and is yieldably mounted on springs at opposite sides of the head I5, the amount of spring pressure being controlled by the hand wheel I62,

Fig. 3. 'As shown in Fig. 1, the pressure roll I29 is driven by means of spiral gear I36, said roll being journaled in the pressure roll assembly, generally indicated by the symbol I63 (Figs. 3 and 9). The pressure roll assembly is slidably mounted in the vertical slideways I55 provided in the head uprights 36. A plunger guide I66, bored for slidably receiving the plunger housing I67, is secured to each outer face of the head uprights 34, as indicated in Fig. 3. The cylindrical plunger housing I 61 is bored for receiving the plunger I58 (Fig. 15) which is tapped for threadedly engagingthe lower end of the stud I69 and counterbored for receiving the compression spring IIll. As will be noted in Fig. 15, the spring I'Ifl is confined within the plunger I58 and the plunger housing Ifi'l by abutment with bottom ll! of the plunger housing bore and the shoulder N2 of the plunger counterbore. The

upper end of the stud IE9 is in engagement with.

journaled in bearing blocks, one of which is shown at 78 in Fig. 3. Keyed to the shaft II'I is the worm I719 which meshes with the worm gear i8! keyed to a longitudinal shaft I82 journaled in and extending through the head uprights 34, a bearing being shown at I30. Keyed to each outer end of the longitudinal shaft I32 is a pinion I83 (Fig. 15), the teeth of which engage the rack teeth I85 provided on the outer diameter of the plunger housing I61.

Thus it will be seen that rotation of the handy wheel I52 will act to elevate and lower the pressure roll assembly I63 in the vertical slideways I65.

Means for limiting the upward travel of the pressure roll assembly may be provided, such as the adjusting screws I86, shown in Figs. 1 and 13. A block I8? is suitably fixed, as by means of the screw I86, to each end of the front plate I88 of the pressure roll assembly, said blocks being tapped for the reception of the adjusting screws- I86. By means of these adjusting screws, the ends of which abut the under surface I84 of the feeding table 33, the lower pressure roll I29 is prevented from coming into contact with the knife 29 as the pressure roll assembly is elevated. The adjusting screws I86 may be set to receive the minimum thickness of leather fed to the feed rolls.

In order to eliminate guess work and the necessity of re-setting the adjusting screws I29 each time a different thickness of leather is fed to the knife, means for quickly and positively setting the pressure roll I29 may be provided. A step flange collar I89, shown in perspective in Fig. 11, is envisioned for accomplishing this object. The flange IQB of the collar is provided with a series of sector-like steps I93, as shown, the flange becoming progressively thicker with each sector, beginning with the thinnest sector I9I and ending with the heaviest sector IE2. The step flange collar I8 is centrally apertured, as at I95, for rotatably mounting same upon the under surface I84 of the feeding table 33, the mounting means being a stud or screw I96, shown in Fig. 13. The collar diameter may be knurled, as at I97, to provide finger gripping means in rotating the collar, said collar being mounted with the upper face I98 thereof in abutment with the under surface I84 of the feeding table 33, in a position whereby the end face of the adjusting screw I86 will contact the substantial median radius of the flange steps I93. A blank or out out sector I99 may be provided between the steps or sectors HI and I92 in order to permit the adjusting screw I86 to directly contact the under surface I84 of the feeding table when the pressure roll I29 is set for the minimum thickness of leather.

Thus it will be seen that it is an easy matter to adapt the pressure roll to various thicknesses of leather by the simple expedient of lowering the pressure roll assembly E83 by means of the hand wheel 162, manually rotating the step flange collars I89 until a predetermined step or sector thickness reaches a point above the adjusting screws I86, and then elevating the pressure roll assembly until the adjusting screws contact the step flange collar I88.

Means for positioning each step or sector substantially centrally of the adjusting screws I86 may be provided, such as the ball 23E peened into a pocket 2M of the collar I89, and backed by the spring 292, the ball being urged by the spring into one of a series of sockets 263 radially disposed upon the under surface of the feeding table 33 in alignment with the steps or sectors I93.

When the pressure roll assembly I53 has been elevated to the point where the adjusting screws I86 contact the feeding table under surface I84 or a step I93 of the flange collar, as the case may be, the hand wheel IE2 is given approximately two full turns for the proper working compression of the springs III in the plunger housing IE'I. This compression, of course, may be varied to suit the individual requirements of various types and textures of leather.

In order to compensate for variations of thickness in a piece of leather being fed to the knife, novel compensating means have been provided, as illustrated in Figs. 9 and 10. It will be noted that the pressure roll I29 comprises a plurality of collars 2%, each independently yieldablevertically, the collars being mounted upon a roll shaft 206, said shaft being provided with longitudinal grooves 207,- which may be substantially V- shaped, as shown in Fig. 9. The inner diameter of the collars is substantially the same in configuration as the outer diameter of the roll shaft 206, but substantially larger in size, to permit vertical movement of the collars upon said shaft. The space between the collars and shaft is indicated at 208. The engagement of the inwardly projecting V-shaped lugs 2% in the collars 285 with the corresponding U-shaped grooves 201 on the roll shaft 2% assures rotation of said collars with rotation of said shaft.

The pressure roll collars 2% are independently urged upwardly by means of frictionally rotatable rollers 2 I I! mounted in spring loaded clevises 2 I I, said rollers being at all times in contact with the roll collars 205, as illustrated, the rollers ZIE and the clevises 2II being equal in number to the pressure roll collars 205. As shown in Fig. 9, the clevises are mounted in a clevis block 2I2, bored to receive the clevis shanks 2&3 and counterbored as at 2I5 to receive the springs 2M in encircled relation with the clevis shanks 2 I3.

As illustrated in 9, the clevis block 252 is interposed between the pressure roll assembly forations.

anemia '11 'front plate I88 and back plate 2I6, said plates being detachably secured to the clevis block by means of the screws 2I'I-2l8. For purposes of clarity, the front plate I88 is mitted from Fig. 10. clevis block 2I2, in alignment with the bores 2I5,

A longitudinal slot 219 is machined in the the slot providing a seat for the clevises 21 I when downward pressure is exerted upon them. The

perforations 222 in said nuts, the nuts being rotated by a rod, such as2-23, inserted in said per- As will be noted in Fig. 10, the jam nuts are adjusted to provide a clearance 225 between the clevis 21 l and the clevis block 2I2 when the clevises are urged upwardly by the springs 2I4. The clearance 225 is substantially equal to the clearance 2238 between the roll shaft 286 and the collars 20E. Clevis pins, upon which the small rollers 2) are mounted, are indicated at 226. Adjustable scraper plates 224 and 224A, suitably fixed to the gauge roll carriage I38 and the pressure roll assembly I63, respectively, as shown in Fig. 9, may be provided.

Fig. clearly delineates the function of the pressure roll I28 on a piece of leather 221 being 'fed to the knife 29. Normally the leather, as it is gripped between the rotating feed rolls, will force the pressure roll collars 205 down upon the roll shaft 285, as shown by the collars "265A. If a thin section in the leather 22? is encounted by the pressure roll I25, the collars which are in contact with the thin portion will force the leather upward against the solid gauge roll I28 by the action of the springs 2M, as indicated by the collars 28513 in Fig. 10, thus assuring a split of leather of uniform thickness. It might be here stated that the upper or usable part of the skived leather is called the split, while the lower part is scrap or waste. In Fig. 10, the split and scrap are indicated by the symbols 221A and 221B,

respectively.

From the foregoing, it will be understood that the arrangement of clevises disclosed herein relieves vital parts of the machine of undue and injurious strains that might otherwise spring the shaft, and particularl the roll shaft 296 which is made relatively light in order to keep the size of collars 285 within reasonable size limits. As previously stated, the collars all have-a definite clearance for lateral displacement upon the shaft 206. This clearance is the same as the limit of reciprocation of the clevises. Thus, the lock nuts 22I are adjustable to preclude upward movement of the olevises beyond the free movement of the collars permitted by the collar clearance at the roll shaft 265, so that none of the force of springs 2I4 is available t arch the shaft upwardly intermediate its ends, when splitting thin leather or when the machine is running idle. Similarly,

the shoulders 2IA of all the clevises providedefinite and substantial stops operative against the heavy rigid clevis block or bar M2, to limit the extent to which .a thick-or hardened workpiece might force the collars 2B5 downwardly, thereby avoiding depression of the collars beyond the downward limits established by the collar. clearances at 225. Thus, there is no danger of collar shaft 206 being sprung or downwardly arched, by passing an unusually thick or hard workpiece through the machine.

In addition to the advantage of individually yieldingly mounted collars 235 forming the pressure roll I29, the entire pressure roll assembly IE3 is yieldably mounted upon the spring loaded plungers I68, as hereinbefore recited and shown in Fig. 3. This pressure roll design assures efficient operation of the machine and a uniform quality of production.

For best results in leather skiving or splitting, the cutting edge of the band knife 28 must be kept keen at all times. For this purpose, grinding wheels 23!! and 23I are provided, said wheels being individuallymotor driven to act upon the lower run of the rotating band knife, as illustrated in Fig. 5. The grinding wheels 23!} and 23I are adjustably mounted in a suitable frame, generally indicated by the symbol 232, said frame being rigidly suspended from the swivel plate 26 and movable therewith. The screws for mounting the grinding wheel frame 232 to the swivel plate '26 are indicated at 234.

'The grinding wheels are'adjusted by means of the hand wheel 233, adjustments being required as the wheels become worn and for the initial setting of new wheels.

As shown, the grinding wheels are mounted to act on both sides of the blade simultaneously to provide a beveled cutting edge, both bevels being substantially equal to produce the best skiving results. Thesegrinding wheels are always in light contact :with the band knife when leather is being fed-to the knife in order to maintain a keen edge thereon.

Novel means for mounting the motors and equalizing the tension on their respective driving belts have been provided. The motor 235 beltdrives the grinding wheel 239, while the motor 236 simultaneously drives the grinding wheel 23 I, their respective belts beingshown at 23? and 238.

0 As shown in Fig. 5, the motor mount 239, like the grinding wheel frame 232, is suspended from the swivel plate '26, but instead of being rigidly mounted, is pivotally mounted at 2 33.

Two substantially vertical bars 240, in spaced parallelism, pivotally depend as a cradle from the motor suspension bracket 24I, said bracket being fixed to the swivel plate 26 by means of the screws 242, rearwardly of the grinding wheel frame 232. The pivot pin is indicated at 243, while a horizontal spacer bar, at the lower ends of the vertical bars 240, is shown at 245. Substantially midway of the pivot pin 243 and the spacer bar 245, and pivoted to the vertical bars 240 therebetween, is the substantially horizontal grinder motor mounting plate 246, the pivot thereof being shown at 241. Upstanding on the pivoted motor plate 246 is the motor 235, while in inverted position directly beneath it the companion motor 236 is mounted, the two motors being rigidly fixed to the pivoted motor plate by means of the screws 248. Proper tension on the motor belts 231 and 23.8 is maintained by means of the tension spring 249, one end of which is attached to the spacer bar 245, while the other end is engaged with the adjustable hook screw 250 disposed in the rearwardly extending tension spring supporting a-rm 25I fixed to the grinding 'Thus if one belt is shorter than the other, the

motor plate 246 will swivel to equalize the ten- 13 sion, the overau tension being achieved through the tension spring 249.-

The knife guides H8, one of which is located at each side of the grinding station, support the knife while it is being ground by the grinding wheels 236 and 235, said guides being suitably fixed to the bed 16 in detachable relation to the grinding wheel frame 232.

As hereinbefore recited, the grinding wheels are adjustable to grind a bevel of substantially equal width on each side of the cutting edge of the knife. Means for indicating a standard bevel has been provided, as shown in Fig. 3, wherein the bevel indicator is depicted by the symbol 252. The width of the knife bevel is controlled by the hand wheel 253, keyed to a transverse bevel control shaft 255 having its front end rotatably mounted in the bevel indicator bearing block 256 fixed to the upper surface of the head base plate 2!. The outer end 251 (Fig. 6) of the bevel control shaft 255 is threaded, and engages a tapped hole in the free end of a cross block 258 fixed to the upper face of the swivel plate 26, transversely thereof, by means of the screws 259.

Rotation of the hand wheel 253, therefore, will move the swivel plate 26 in the head base plate groove 25. Movement of the swivel plate 26, of course, also moves the grinding wheels and motors depending therefrom, but does not move the band knife 29, which travels in a fixed path. Such movement of the grinding wheels, accompanied by slight separation thereof incident to manipulation of handwheel 253, affects the length of the bevel on the knife blade. Counter-clockwise rotation of the hand wheel 253 shortens the bevel, while clockwise rotation lengthens it. Experience has proved that a bevel of approximately one-eighth of an inch in length is the most satisfactory for average work.

In orderto definitely indicate the length of the bevel at all times, the bevel indicator 252 (Fig. 3) has been added to the bevel control means. This comprises a bevel indicator rod 266 having one end in slidable engagement with an aperture provided in the bevel indicator bearing block 256, and its opposite end adjustably fixed to the cross block 258 (Fig. 6) at the rear of the swivel plate 26, as by means of the set screw 26L As shown in Figs. 3 and 6, the indicator rod 266 is in parallel relation to the bevel control shaft 255.

In setting the bevel indicator, the grinding wheels are adjusted by rotating the bevel control hand wheel 253 to provide the desired bevel on the band knife, the set screw 26! in the cross block 256 being left untightened. When the desired bevel has been attained, the end face of the indicator rod 260 is brought flush with the outer face of the bevel indicator bearing block 256 and the set screw 26f tightened upon the opposite end of the bevel indicator rod in the cross block 258 at the rear of the machine.

Thus the bevel indicator may be set to indicate a bevel of substantially one-eighth inch in length upon the band knife cutting edge when the indicator rod end face is flush with the outer face of the bevel indicator bearing block 256. Thereafter, when the bevel control hand wheel 253 is rotated clockwise, the bevel indicator rod 260, in fixed relation to the grinding wheels, will recede into the bevel indicator bearing block 256, the depth of the recession equalling the increase in the length of the bevel. Conversely, counterclockwise rotation of the hand wheel 253 will cause indicator rod 260 to protrude from the bevel indicator bearing block 256, the length of the protrusion indicating the decrease in the length of the bevel.

As hereinbefore recited, the head I5 is swivel mounted, making possible various adjustments heretofore unattainable in former leather skiving devices. Figs. 7 and 8 show the method of mounting the swivel head. Upon the front wall of the bed [6, substantially centrally thereof, is mounted a swivel bracket 263, vertically apertured to receive the swivel pin 265. The upper surface of the swivel bracket 263 is coplanar with the surface 19 of the bed [6 upon which the swivel plate 26 is disposed. As shown in Figs. '1 and 8, the forward end 21 of the swivel plate rests upon the upper surface of the swivel bracket. The forward end of the swivel plate is slotted, as at 266, to slidably engage the pivot block 261, said block being centrally apertured to rotatably receive the swivel pin 265. The pivot block is of substantially the same thickness as the swivel plate 26.

Forward and rearward movement of the head I5 upon the bed i6 is selectively controlled by means of the head control hand wheel 268, keyed to the shaft 266, said shaft being intermediate the shafts l1? and 255, and parallel therewith. The shaft 269, adjacent its outer end, takes a bearing in the head control bearing block 216, which is in fixed relation with the bed [6 by means of the swivel pin 265. As shown, the bearing block 216 is apertured to receive the upper end of the swivel pin 265 which extends upwardly through the swivel bracket 263 and the pivot block 261. The swivel pin 265 may be secured against displacement in the bearing block 216, as by means of the lock pin 21f.

The inner end of the head control shaft 266 is threaded, as at 212, for engagement with the internal threads of a pull block 213 in fixed relation with the head 55, said pull block being in the form of a nut bolted or otherwise secured to the upper surface of the head base plate 2?. Means for precluding the shifting of the shaft 269 in the bearing block 216 have been provided. A counterturned diameter21'5 extends through the transversely apertured bearing block 216, the shoulder 2'l6 on the shaft abutting the rear face of said block. Interposed between the front face of the bearing 216 and the hand wheel 266 upon the diameter 2%, is a spacer collar 211, said hand wheel being held in abutment with the outer end face of said collar by means of the nut 218 turned upon the threaded outer end of the shaft 266.

Thus it will be seen that rotation of the hand wheel 266 transmits movement to the head l5 upon the bed surface If: by reason of the threaded engagement of the shaft 266 with said head. When the head i 5 is thus moved, the swivel plate 26 is also moved in unison, because of the fixed connection of the head 15 and the swivel plate 26 through the bevel control shaft 255. However, rotation of the bevel control hand wheel 253 will transmit motion to the swivel plate 26, but not to the head I5.

When the swivel plate 26 is moved, either independently of the head it or in association with the said head, it is guided in its transverse movement by the pivot block 261 which slidably engages the slot 266 in the forward end 21 of said swivel .plate, and by the pair of opposed set screws 286, directed at the sides of the swivel plate, at the far end 28 of said swivel plate, as shown in Figs. 5 and :6. {-rhese set screws 28!] which control the alignment of the head t5, threadedly engage the vertical blocks 23f mounted upon the rear wall 282 of the bed H5 at opposite S des oi the swivel plate 26, the mounting means of which may be screws 283. A slight clearance is maintained between the ends of the set screws 2G9 and the sides of swivel plate 25 to permit free slidable movement of said swivel plate between said set screws.

The head is swivel mounted to insure that the cutting edge of the band knife 29 is parallel with the center line of the feed rolls I28 and 433 for the full length of the rolls when the machine is set for splitting leather of substantially uniform thickness. Thus the head i5 may be swiveled to the right or left, as the case may be, in aligning the band knife with the feed rolls, by adjusting the set screws 230. After adjustments have been made, the set screws may be locked against rotationiby means of the lock nuts 285.

If the operator desires to obtain splits of different thicknesses, the head may be swiveled, by means of the swivel plate adjusting screws 280, to obtain an unparallel or cocked relationship between the cutting edge of the band knife and the center line of the feed rolls. Such an adjustment produces a heavier split at one end of the feed rolls than at the other with the result that individual leather sheets may be fed simultaneously to the knife at both sides of the feed ing table 33, making possible the production of several thicknesses of splits with one setting of the machine. Obviously this is an advantage in increasing the production of the operator.

A sheet of leather, on being fed to the machine, is gripped between the feed rolls I28 and E29, and forced against the cutting edge of the knife, being thereby divided into two thinner sheets. The upper or usable sheet, called the split, will be discharged into the top tray 286 (Fig. 2), while the lower or scrap sheet will be discharged into the bottom trap 281, both of said trays being at the rear of the machine, as shown.

As the knife blade 29 becomes worn, the head l5 may be retracted by means of the head con" trol hand wheel 258 to compensate for the knife wear. When the knife blade is replaced with a new one, the head 15 will be brought forward to the original setting by the same means.

The machine constructed as disclosed herein is highly productive and will perform many operations which heretofore had to be assigned to other machines especially adapted for splitting different grades and weights of leather. Re= peated handling of the products is thereby avoided, and the machine therefore is kept in continuous operation with a resultant saving of labor and operating expense. Various other advantages have been set forth previously herein, and still others will be evident to those skilled in the art.

It is to be understood that various modifications and changes in the structural details of the machine may be made, within the scope of the having a section running in substantial parallelism with one of the feed rolls, motion trans-- mission means for elevating and lowering the carriage to vary the spacing of the feed rolls rela tively, a vertically bored extension on the carriageoverlying the feed table, a vertical pressure pin slidable in the bore of said extension and having an end extending downwardly therefrom into contact with the feed table, yielding means urg ing the end of the pressure pin against the feed table to urge the carriage and the upper feed roll toward an elevated position to overcome backlash in the motion transmission means, and a stop upon the pin to limit retractile movement of the pin in opposition to the force of the yielding means to preclude contact of the upper feed roll with the lower feed roll and with the and ni e- 2. In a material splitting machine, the com bination of a bed, a head superposed upon the bed, a feed table attached to the head, a carriage slidable upon the head toward and from the bed, a lower feed roll journaled for rotation and supported upon the head, an upper feed roll on the carriage, a continuously moving band knife having a section running in substantial parallelism with one of the feed rolls, motion transmitting means for elevating and lowering the carriage to vary the spacing of the feed rolls relatively, a vertically bored extension on the carriage overlying the feed table, a vertical pres;- sure pin slidable in the bore of said extension and having an end extending downwardly therefrom into contact with the feed table, and yielding means urging the end of the pressure pin against the feed table to urge the carriage and the upper feed roll toward an elevated position to overcome backlash in the motion transmitting me ns 3. In a materiaksplitting machine, the com- 'bination of a bed, a head superposed upon the bed, a feed table attached .to the head, a carriage slidable upon the head toward and from the bed, a lower feed roll journaled for rotation and sup ported upon the head, an upper feed roll on the carriage, a v continuously moving band knife having .a section running in substantial parallelism with one of the feed rolls, motion transmission means for elevating and lowering the carriage to vary the spacing'of the feed rolls relatively, a vertically bored extension on the carriage overlying the feed table, a vertical pressure pin slidable in the bore of said extension and having an end extending downwardly therefrom to contact the feed table, and yielding means constantly urging the end of the pressure pin into forceful contact with said table, thereby to constantly urge the carriage and the upper feed roll toward an elevated position to overcome backlash in the motion tra smission means.

4. In a material-splitting machine, the combination of a bed, a head superposed upon the bed, a feed table attached to the head, a carriage .slidable upon the head toward and from the bed, a lower feed roll journaled for rotation and sup: ported upon the head, an upper feed roll on the carriage, a continuously moving band knife having a section running in substantial parallelism with one of the feed rolls, motion transmission means for elevating and lowering the carriage to vary the spacing of the feed rolls relatively, a vertically bore extension on the carriage over: lying the feed table, a vertical pressure pin slidable in the bore of said extension and having an end extending downwardly therefrom to con:-

tact the feed table, yielding means constantly urging the end of the pressure pin into forceful contact with said table, thereby to constantly urge the carriage and the upper feed roll toward an elevated position to overcome backlash in the motion transmission means, and adjustable stop means operative upon the pressure pin to limit retractile movement of the pin in opposition to the force of the yielding means aforesaid.

5. In a material-spliting machine, the combination of a bed, a head superposed upon the bed, a feed table attached to the head, a carriage slidable upon the head toward and from the bed, a lower feed roll journaled for rotation and supported upon the head, an upper feed roll on the carriage, a continuously moving band knife having a section running in substantial parallelism with one of the feed rolls, motion transmission means for elevating and lowering the carriage to vary the spacing of th feed rolls relatively, a vertically bored extension on the carriage overlying the feed table, a vertical pressure pin slidable in the bore of said extension and having an end extending downwardly therefrom to contact the feed table, yielding means constantly urging the end of the pressure pin into forceful contact with said table, thereby to constantly urge the carriage and the upper feed roll toward an elevated position to overcome backlash in the motion transmission means, and stop means operative upon the pressure pin to limit retractile movement of the pin in opposition to the force of the yielding means aforesaid.

6. In a material splitting machine, the combination of a stationary bed, a head superposed upon the bed, a carriage slidable upon the head toward and from the bed, a lower elongate feed roll journaled for rotation and supported upon the head, a driven upper elongate feed roll of substantially the same effective length as the lower part of the head, the spacing between said pins 5 being approximately equal to the effective length of the upper and lower rolls so as to limit the width of material insertable between the rolls, and yielding means constantly urging the lower ends of the pins into forceful contact with said part of the head in opposition to the lowering movement of the carriage imparted by the motion transmitting train. I

'7. In a material splitting machine, the combination of a stationary bed, a head superposed upon the bed, a carriage slidable upon the head toward and from the bed, a lower elongate feed roll journaled for rotation and supported upon the head, a driven upper elongate feed roll of substantially the same effective length as the lower feed roll, means rotatably supporting the upper feed roll upon the carriage, a continuously moving band knife having a section running in substantial parallelism with one of the feed rolls, a motion transmitting train for elevating and lowering the carriage to vary the spacing between if n) the feed rolls, a pair of pressure pins mounted upon the carriage for sliding vertical movement, said pins each having a lower end to contact a part of the head, the spacing between said pins being approximately equal to the effective length of the upper and lower rolls, so as to limit the width of material insertable between the rolls, yielding means constantly urging the lower ends of the pins into forceful contact with said part of the head in opposition to the lowerin movement of the carriage imparted by the motion transmitting train, and means limiting said lowering movement of the carriage to preclude contact of the upper driven roll with the moving band knife.

8. In a material splitting machine, the combination of a stationary bed, a head normally stationary upon the bed in elevated position thereon, a carriage slidable upon the head toward and from the bed, a lower feed roll journaled for rotation and :adjustably supported upon the head, a driven upper feed roll on the carriage, a continuously moving band knife having a section running in substantial parallelism with one of the feed rolls, a motion transmitting train for elevating and lowering the carriage to vary the spacing between the feed rolls, a pair of pressure pins mounted upon the carriage for sliding vertical movement, said pins each having a lower end to contact a part of the head, the pins being spaced apart a distance for limiting the width of material to be fed to the rolls, yielding means constantly urgin the lower ends of the pins into forceful contact with said part of the head in opposition to the lowering movement of the carriage, and step means operated manually to establish the positions of adjustment of the lower feed roll relative to the upper feed roll.

9. In a material splitting machine, the combination of a stationary bed, a head normally stationary upon the bed in elevated position thereon, a carriage slidable upon the head toward and from the bed, a lower feed roll journaled for rotation and adjustably supported upon the head, a driven upper feed roll on the carriage, a continuously moving band knife having a section running in substantial parallelism with one of the feed rolls, a motion transmitting train for elevating and lowering the carriage to vary the spacing between the feed rolls, a pair of pressure lpins mounted upon the carriage for sliding vertical movement, said pins each havin a lower end to contact a part of the head, thepins being spaced apart a distance for limiting the width of material to be REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Boettger Oct. 24, 1939 Number 

